Electric watch with electrodynamic motor

ABSTRACT

An electric watch with an electrodynamic motor includes a stationary coil and moveable magnets. The driving mechanism portion is situated at the same level in the motor as the coil and is made of non-magnetic and insulating material for preventing perturbations due to magnetic causes and to currents of Foucault.

United States Patent 11 1 [111 3,859,784 Schneiter 1 Jan. 14, 1975 [5 1 ELECTRIC WATCH WITH 3,002,335 10/1961 Kripak 58/2 ELECTRODYNAMIC MOTOR 3,059,413 10/1962 Deturile r 58/28 D 3,708,974 1/1973 Fu lmorl 58/28 R [75] Inventor: Ali Schneiter, Neuchatel,

Switzerland 1 Primary ExaminerEd1th S1mmons Jackmon AsslgneeZ s f t l il- Neuchatel, Attorney, Agent, or Firm-Silverman & Cass, Ltd.

w1 zer an [22] Filed: Dec. 11), 1973 [57] ABSTRACT [21] Appl. No; 423,132

An electric watch with an electrodynamic motor includes a stationary coil and moveable magnets. The 58/28 ds f driving mechanism portion is situated at the same 58 i D level in the motor as the coil and is made of non- 1 0 3 magnetic and insulating material for preventing perturbations due to magnetic causes and to currents of [56] References Cited Fmcault' UNITED STAT PATENTS 3 Claims, 3 Drawing Figures 2,847,818 8/1958 Junghans et al. 58/28 D PATENIED JAN 1 4mm SHEET 2 BF 2 The present invention relates to an electric watch with electrodynamic motor comprising a transductor the coil of which is stationary and the magnet or magnets of which are carried by the movable element.

This watch is characterized by the fact that it comprises a driving mechanism by the intermediary of which the said movable element drives the elements indicating the time, this driving mechanism being situated at the level, measured in height, of the said coil and being made of non magnetic and insulating material at least in its portion swept by the field of the movable magnet, the whole in such a way that perturbations due to magnetic causes and to currents of Foucault be prevented.

The drawing shows, by way of example, one embodiment of the object of the invention.

FIG. 1 is a plan view, with a partial section according to the broken line 1-1 of FIG. 2, of a part of an electric watch.

FIG. 2 is a sectional view along line 11-11 of FIG. 1, and

FIG. 3 is a sectional view, similar to this one of FIG. 2, of a conventional construction, illustrating the drawbacks of such an arrangement with respect to the present construction.

The watch shown comprises a frame including a base plate 1 and a bridge 2 between, which is rotatably mounted the balance comprising a shaft 3 carrying two plates 4 on each of which are mounted two permanent magnets 5, connected to each other by an armature plate 6, and a counterweight 7. A cake shaped coil 8 is partially engaged between the two plates 4 of the balance. This coil comprises a first winding intended to produce, by induction, a signal at the passage of the magnets, during the oscillations of the balance, which signal is amplified by a not represented electronic circuit and sent into a second winding of the said coil which then applies to the said magnets a maintaining pulse.

The counting of the oscillations of the balance in view of the time display is effected by means of an oscillating lever 9, having two arms, rotatably mounted at 10 between the base plate 1 on the one hand and a bridge 11 of the frame of the movement on the other hand, and one of the arms of which is operated by a pin 12, parallel to the shaft of the balance, carried by a dsic 3a provided on this shaft. A blade spring 13 acts on the lever 9 for maintaining it applied against the pin 12. The second arm of the lever 9 carries, secured to three pins 14, a blade spring 15, acting as a pawl, cooperating with a ratchet counting wheel 16 driving the gearing of the movement the first element of which, i.e., the seconds element, designated by 17, has been only represented. A retaining pawl constituted by an elastic blade 18 carried by an elastic arm 19 acts also on the counting wheel 16. An excentric member 20 permits to ad- 5 just very precisely the position of the pawl 18.

So as to prevent perturbations due to magnetic causes and to currents of Foucault since the lever 9 passes between the magnets 5 during the oscillations of the balance, this lever is realized in a non magnetic and insulating material, for instance in polyacetal plastic such as DELRIN (Registered Trademark).

- One sees that, in this arrangement, the driving mechanism, that is to say the lever 9 and the pin 12, is situated at the level, measured in height, of the coil 8. There results an important economy of height with respect to the classic constructions in which, as shown in FIG. 3, the said driving mechanism is situated below the lower plate of the balance. One sees that, in this classic execution, a counting pallets 21, rotatably mounted at 22, is operated by a pin 23 carried by a plate 24 and operates itself, by means of its lifts 25, the counting wheel, designated by 26. In this arrangement, all this mechanism is situated below the lower plate 27 of the balance the shaft of which is designated by 28.

One sees that the height h of the movement of FIG. 2 is lower than the height H of the movement of FIG. 3, the general dimensions of the balance being otherwise the same.

What I claim is:

1. Electric watch with electrodynamic motor comprising a transductor which has a movable element and the coil of which is stationary and at least one magnet carried by the movable element, characterized by the fact that it comprises a driving mechanism by the intermediary of which the said movable element drives the elements indicating the time, this driving mechanism being situated at the level, measured in height, of the said coil and being made of non-magnetic and insulating material at least in its portion swept by the field of the movable magnet, for preventing perturbations due to magnetic causes and to currents of Foucault.

2. Electric watch as claimed in claim 1, wherein said movable element includes a double plate driving balance, characterized by the fact that the said driving mechanism is situated between the two plates.

3. Electric watch as claimed in claim 2, characterized by the fact that the said driving mechanism is constituted by a pin parallel to the axis of the balance, carried by a disc secured to the shaft of the balance, between the two plates of this latter, and by an oscillating two arms lever, one arm of which cooperates with the said pin, a resilient device for maintaining said one arm applied against said pin and the other arm of which carries a pawl operating a ratchet counting wheel.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,859,784

DATED January 14, 1975 INVENTOR(S) ALI SCHNEITER It is certified that error appears in the above-idenfified patent and that seid Letters Patent are hereby corrected as shown below:

In the title block area, two lines below u 28 a u I I 0 0 0 Signed and Scaled this seventh Day of 0ct0'ber1975 [SEAL] A rtes t:

RUTH C. MASON I v C. MARSHALL DANN Arresting Officer Commissioner oflalents and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,859,784

DATED January 14, 1975 INV ENTOR( S) ALI SCI-INEITER II is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the title block area, two lines below Dec. 28, 1972 Switzerland. .018986/72 Signed and Scaled this seventh Day Of 0ct0 ber1975 [SEAL] A ttest.

RUTH C. MASON C. MARSHALL DANN Arremng Officer (0mm [winner of Patents and Trademarks 

1. Electric watch with electrodynamic motor comprising a transductor which has a movable element and the coil of which is stationary and at least one magnet carried by the movable element, characterized by the fact that it comprises a driving mechanism by the intermediary of which the said movable element drives the elements indicating the time, this driving mechanism being situated at the level, measured in height, of the said coil and being made of non-magnetic and insulating material at least in its portion swept by the field of the movable magnet, for preventing perturbations due to magnetic causes and to currents of Foucault.
 2. Electric watch as claimed in claim 1, wherein said movable element includes a double plate driving balance, characterized by the fact that the said driving mechanism is situated between the two plates.
 3. Electric watch as claimed in claim 2, characterized by the fact that the said driving mechanism is constituted by a pin parallel to the axis of the balance, carried by a disc secured to the shaft of the balance, between the two plates of this latter, and by an oscillating two arms lever, one arm of which cooperates with the said pin, a resilient device for maintaining said one arm applied against said pin and the other arm of which carries a pawl operating a ratchet counting wheel. 